<ul class="question-controls list-group">
  <li *ngFor="let control of controls" class="list-group-item">
    <a [ngClass]="control.iconClass" (click)="onAddQuestion(control)">
      <i class="icon iconfont" [ngClass]= "control.iconClass"></i> {{control.label}}
    </a>
  </li>
</ul>